santoki said:
We are planning to leave my wife's US account open in order to pay/receive taxes for 2012, but what obligations does she have to pay tax to the US going forward? If she's not a resident there and not planning to be one, do we still have to continue to file taxes for the rest of her life? Or can she claim to be a non-resident and be exempt from paying any taxes?
Is she a US Citizen? If so, she has an ongoing obligation to comply with US tax law. The US is distinctly different than Canada - it taxes you on your
world wide income regardless of your place of residence. Generously, it allows you to offset taxes paid to other jurisdictions. However, there are numerous arcane requirements, including filing a TFAR if you have signatory authority over someone else's account (e.g., if you owned your own business) or if the aggregate balance in your own accounts exceeds US$10,000 per year. The penalties for failing to properly file the TFAR each year are onerous and can outstrip the value of the account rather quickly.
Estate tax planning is another complex area. If her estate is worth less than US$1,000,000 then she's fine (it's US$5 million until 31 December, but the changes to estate taxes that come into effect on 1 January 2013 are part of that "fiscal cliff" thing they're arguing about - and I hope she doesn't die before January 1!)
It's actually not the tax payments that turn out to be the painful part - it's the information returns. The US is so convinced they're being scammed - and they are - they have created these draconian information return forms 3520, 5471, 8891 and the new 8938 have almost nothing to do with income tax and everything to do with information (3520 and 5471 can lead to potential taxation, but unless you have a trust account - like a TFSA or RESP - the 3520 won't apply and unless you have your own corporation - like a family business - 5471 won't apply. 8891 is for RRSPs and 8938 is for anything else she might have that's worth $200k or more.) But these forms apply to people who aren't scamming the system and frankly don't have the financial means to do so.
Of course, the real way the US is being scammed is by allowing people to set up complex tax shelters (e.g., Mitt Romney) overseas that allow very rich people to pay little or nothing in tax.
Her children will be American by descent as well (at least under current laws) and thus will have the same requirements. That's where those draconian penalties (in some cases 50% of the account balance
per year or $10,000 for a missing FBAR, up to 7 years back...) Imagine a 350% penalty simply because you didn't file a document you didn't even know you HAD to file. There are forgiveness clauses in the regulations, but you owe the money, they just choose to forgive some of it.